Lions expect concussion to end Marcus Adams' career

They have lingered for seven months, since the 29-year-old last took the field in round 21 last season.

"He has good days and not so good days, so probably not a lot has changed at this point in time," Fagan told SEN's Crunch Time on Saturday.

"I'll be amazed if he plays this year and, to be fair, I'll be amazed if he plays again.

"My main concern is that he gets right and can live a really good and fulfilling life and not be troubled by this for a long time."

Former Lions defenders Justin Clarke, Jack Frost and Matt Maguire all retired in the past decade because of ongoing effects of concussion.

Fears over Adams' future come as the AFL faces multiple class actions from ex-players seeking compensation over health issues related to on-field concussion.

"(Adams) played football in a really brave way and was one of those guys who would always go back with the flight (of the ball) in the air," Fagan said.

"I'm just hoping that he gets right and can be fit and healthy for normal, everyday tasks.

"If he plays footy again, well, that's an absolute bonus.

"But probably as a coach I'd feel pretty nervous about putting him back out on the ground again after what he's been through."

Adams was substituted off with a rib injury in his most recent appearance, in a win over Carlton last August.

In the days that followed, Adams began experiencing concussion symptoms that have lingered ever since.

The concussion followed a series of injury setbacks that have cruelled the former Western Bulldogs defender's career.

Adams was restricted to 27 games across three seasons with the Bulldogs, then missed all but one game of the 2020 season with a foot injury.

He has played a total of 73 games over seven seasons.

Adams' absence has left a hole in Brisbane's defence alongside mainstay Harris Andrews.

Jack Payne remains a work in progress while Irishman Darragh Joyce was recruited to add depth when Adams was put on the inactive list.